GI (P00074) Protein Card

General Information
Name GI
Organism Conus geographus (Geography cone)
Organism region Indo-Pacific
Organism diet piscivorous
Protein Type Wild type
Protein precursor GI precursor (2975)
GI precursor (5714)
Notes Paralysis in vertebrates. This is the very first caracterised toxin from a Conus venom (Gray et al. 1981).

Classification
Conopeptide class conotoxin
Gene superfamily A superfamily
Cysteine framework I
Pharmacological family alpha conotoxin

Sequence
ECCNPACGRHYSC(nh2)
Modified residues
positionsymbolname
14nh2C-term amidation
Sequence evidence protein level
Average Mass 1437.59
Monoisotopic Mass 1436.48
Isoelectric Point 8.09
Extinction Coefficient [280nm] 1490.00

Activity

IC50: Nicotinic acetylcholine receptors

TargetOrganismIC50AgonistRef
α1β1γδM. musculus20nM500nM AchJohnson,D.S. et al. (1995)
(site 1)1.3nM+/-0.310nM [125I]-R-BgtxGroebe,D.R. et al. (1997)
(site 2)60uM10nM [125I]-R-BgtxGroebe,D.R. et al. (1997)
T. marmorata(site 1)4.5nM+/-1.310nM [125I]-R-BgtxGroebe,D.R. et al. (1997)
(site 2)87nM+/-2410nM [125I]-R-BgtxGroebe,D.R. et al. (1997)
α2β2R. norvegicus>5uM300uM AchJohnson,D.S. et al. (1995)
α2β4R. norvegicus>5uM300uM AchJohnson,D.S. et al. (1995)
α3β2R. norvegicus>5uM300uM AchJohnson,D.S. et al. (1995)
α3β4R. norvegicus>5uM300uM AchJohnson,D.S. et al. (1995)
α4β2R. norvegicus>5uM300uM AchJohnson,D.S. et al. (1995)
α4β4R. norvegicus>5uM300uM AchJohnson,D.S. et al. (1995)
α7R. norvegicus>5uM500uM AchJohnson,D.S. et al. (1995)
α9R. norvegicus>5uM100uM AchJohnson,D.S. et al. (1995)

Synthetic variants
GI [N4>Benzoylphenylalanine]ECC(Pbf)PACGRHYSC
GI [R9A]ECCNPACGAHYSC(nh2)
GI [S12>Benzoylphenylalanine]ECCNPACGRHY(Pbf)C
GI antitoxic analogCANPACGRHYS(nh2)

References
Gray,W.R., Luque,A., Olivera,B.M., Barrett,J. and Cruz,L.J. (1981) Peptide toxins from Conus geographus venom J. Biol. Chem. 256:4734-4740
Groebe,D.R., Gray,W.R., and Abramson,S.N. (1997) Determinants involved in the affinity of alpha-conotoxins GI and SI for the muscle subtype of nicotinic acetylcholine receptors Biochemistry 36:6469-6474
Guddat,L.W., Martin,J.A., Shan,L., Edmundson,A.B. and Gray,W.R. (1996) Three-dimensional structure of the alpha-conotoxin GI at 1.2 A resolution Biochemistry 35:11329-11335
Pardi,A., Galdes,A., Florance,J. and Maniconte,D. (1989) Solution structures of alpha-conotoxin G1 determined by two-dimensional NMR spectroscopy Biochemistry 28:5494-5501
Gehrmann,J., Alewood,P.F. and Craik,D.J. (1998) Structure determination of the three disulfide bond isomers of alpha-conotoxin GI: a model for the role of disulfide bonds in structural stability J. Mol. Biol. 278:401-415
Johnson,D.S., Martinez,J., Elgoyhen,A.B., Heinemann,S.F. and McIntosh,J.M. (1995) alpha-Conotoxin ImI exhibits subtype-specific nicotinic acetylcholine receptor blockade: preferential inhibition of homomeric alpha 7 and alpha 9 receptors Mol. Pharmacol. 48:194-199

Internal links
Protein Precursor GI precursor (2975)
GI precursor (5714)
Nucleic acids
Structure THE 1.2 ANGSTROM STRUCTURE OF G1 ALPHA CONOTOXIN
ALPHA CONOTOXIN GI: 2-3;7-13 DISULFIDE BOND ISOMER, NMR, 25 STRUCTURES
ALPHA CONOTOXIN GI: 2-7;3-13 (NATIVE) DISULFIDE BOND ISOMER, NMR, 35 STRUCTURES
ALPHA CONOTOXIN GI: 2-13;3-7 DISULFIDE BOND ISOMER NMR, 24 STRUCTURES

External links
UniProtKB/Swiss-Prot P01519
Ncbi 1XGA_A, 1NOT_A, 1XGB_A, 1XGC_A

Tools